/Engine/Source/Developer/PhysicsUtilities/Public/ConvexDecompTool.h
Utility for turning arbitrary mesh into convex hulls.  InBodySetup BodySetup that will have its existing hulls removed and replaced with results of decomposition.
void DecomposeMeshToHulls ( [UBodySetup](API\Runtime\Engine\PhysicsEngine\UBodySetup) * InBodySetup, const [TArray](API\Runtime\Core\Containers\TArray)< FVector3f > & InVertices, const [TArray](API\Runtime\Core\Containers\TArray)< uint32 > & InIndices, uint32 InHullCount, int32 InMaxHullVerts, uint32 InResolution )